bash
n.— «Existing dealers in Dumfries, keen to meet demand, have been cutting the drug with potentially fatal fillers, or “bash” as it is known on the street, which can lead to thrombosis. The main agent used is diazepam, but other substances being used include codeine, brick dust and, in one gruesome instance which saw a young woman developing blocked veins, Polyfilla.» —“‘One young lad said he was on a mission to die'” by Martyn McLaughlin The Herald (Glasgow, Scotland) July 12, 2006. (source: Double-Tongued Dictionary)
Further reading
How colors got their names, and a strange way to write. The terms blue and orange arrived in English via French, so why didn’t we also adapt the French for black and white? • Not every example of writing goes in one direction across the page...
Funny cat videos and cute online photos inspire equally adorable slang terms we use to talk about them. • Also, when a salamander is not a salamander, the story of an Italian term for a dish towel used halfway across the world, Bozo buttons...